One of the prior art method used heretofore to affix ferrules to fuse casings consists in providing the casings with circular grooves, placing more or less resilient inserts into the grooves, and working the axially inner edges of the ferrules into these grooves and into firm engagement with the resilient inserts therein.
A modification of this method consists in interposing relatively elastic elements between the rims of the casing and the end surfaces of the ferrules, and thereafter working the axially inner edges of the ferrules into grooves provided in the casing of the fuse.
Both method have limitations of which the most outstanding resides in the fact that the first method calls for resilient grooves inserts or annuli, and the second method calls for resilient washers, O-rings, or the like.
It is, therefore, one of the primary objects of this invention to provide electric fuses, not requiring any additional parts for stressing the lateral walls of the ferrules, i.e. wherein such stressing is effected by parts of the ferrules themselves.